Haviland Durachlor Combat ExtraThe Durachlor Combat Extra product is powerful all purpose algaecide that can target any form of stubborn algae. This non staining liquid product is also fast acting and long lasting on the toughest algae formations. Not only will this remove all types of algae, but it includes a special clarifying agent that will help clear up the water fast. All Purpose algaecide Fast acting and long lasting formula Includes a special clarifying agent that helps